Drug retention of 7 biologics and tofacitinib in biologics-naive and biologics-switched patients with rheumatoid arthritis: the ANSWER cohort study

Background: This multi-center, retrospective study aimed to clarify retention rates and reasons for discontinuation of 7 biological disease-modifying antirheumatic drugs (bDMARDs) and tofacitinib (TOF), one of the Janus kinase inhibitors, in bDMARDs-naive and bDMARDs-switched patients with rheumatoid arthritis (RA). Methods: This study assessed 3897 patients and 4415 treatment courses with bDMARDs and TOF from 2001 to 2019 (2737 bDMARDs-naive courses and 1678 bDMARDs-switched courses [59.5% of switched courses were their second agent], female 82.3%, baseline age 57.4 years, disease duration 8.5 years; rheumatoid factor positivity 78.4%; Disease Activity Score in 28 joints using erythrocyte sedimentation rate 43; concomitant prednisolone [PSL] dose 6.1 mg/day [usage 42.4%], and methotrexate [MTX] dose 8.5 mg/week [usage 60.9h]). Treatment courses included abatacept (ABT; n = 663), adalimumab (ADA; n = 536), certolizumab pegol (CZP; n = 226), etanercept (ETN; n = 856), golimumab (GLM; n = 458), infliximab (IFX; n = 724), tocilizumab (TCZ; n = 851), and TOF (n = 101/only bDMARDs-switched cases). Drug discontinuation reasons (categorized into lack of effectiveness, toxic adverse events, non-toxic reasons, or remission) and rates were estimated at 36 months using Gray's test and statistically evaluated after adjusted by potential clinical confounders (age, sex, disease duration, concomitant PSL and MTX usage, starting date, and number of switched bDMARDs) using the Fine-Gray model. Results: Cumulative incidence of drug discontinuation for each reason was as follows: lack of effectiveness in the bDMARDs-naive group (from 13.7% [ABT] to 26.9% [CZP]; P < 0.001 between agents) and the bDMARDs-switched group (from 18.9% [TCZ] to 46.1% [CZP]; P < 0.001 between agents); toxic adverse events in the bDMARDs-naive group (from 4.6% [ABT] to 11.2% [ETN]; P < 0.001 between agents) and the bDMARDs-switched group (from 5.0% [ETN] to 15.7% [TOF]; P= 0.004 between agents); and remission in the bDMARDs-naive group (from 2.9% [ETN] to 10.0% [IFX]; P < 0.001 between agents) and the bDMARDs-switched group (from 1.1% [CZP] to 33% [GLM]; P= 0.9 between agents). Conclusions: Remarkable differences were observed in drug retention of 7 bDMARDs and TOF between bDMARDsnaive and bDMARDs-switched cases.